DESCRIPTION: The ultimate goals of this proposal are to identify organizational principles of information flow and integration in sensorimotor systems of the brain. The model perhaps best suited for this is the oculomotor system, where visual percepts are integrated with high order behavioral processes for the production of highly precise saccadic eye movements. By studying this "simple" behavior, we hope to understand some of the general mechanisms by which the brain produces all behavior. Studying the brain in awake, behaving subjects allows a degree of insight into high order brain functions that is not possible in other experimental models. Globally, these studies help us to understand the biological solutions for the problem of information flow in the brain and the transformation of visual signals for movement control. This is important not only for understanding the biology of eye movements in humans, but to the problem of movement control and behavior in general. We propose to study the activity of individual neurons in the posterior parietal cortex and the superior colliculus during simple visual and eye movement behavior. We have shown that parietal neurons are part of the process for translating the spatial position of visual stimuli into the commands for moving the eyes. We will identify individual neurons that project from parietal cortex to other oculomotor centers (the superior colliculus and the frontal eye fields). By studying these neurons we can determine the transfer of information from one brain area to the next. We will use both empirical and modeling techniques. We will construct models of the transformations determined from the biological experiments. We will then use the models to make new predictions that can be tested in the lab.